Overview
This lecture covers the clinical methods for assessing various sensory modalities in a neurological exam, including techniques for examining touch, temperature, pain, vibration, proprioception, and higher-order sensory functions.
Sensory Examination Overview
- Sensory testing includes light touch, temperature, pain, vibration, proprioception, graphesthesia, stereognosis, double simultaneous stimulation, and balance.
- All sensory tests, except balance, are performed bilaterally to compare both sides.
- Instruct patients to close their eyes during tests to eliminate visual cues.
Light Touch
- Use a cotton swab to gently stroke skin in the distribution of cutaneous nerves.
- Ask the patient to say "yes" each time touch is felt; test both arms and legs.
- Compare both sides for differences in sensation.
Temperature Sensation
- Use the cold end of a metal tuning fork to touch the skin and test for cold sensation.
- Ask the patient to say "cold" when the stimulus is felt; test on both arms and legs.
- Assess if intensity changes when moving from distal to proximal sites.
Pain Sensation
- Use a sharp object (pin or broken cotton swab) to touch the skin in different locations.
- Patient says "yes" when pain is felt; test circumferentially and compare both sides.
- Check for changes in intensity from distal to proximal.
Vibration Sensation
- Apply a vibrating 128 Hz tuning fork to bony prominences (thumbs, toes, medial malleoli).
- Patient indicates if vibration is felt; alternate with a non-vibrating fork for comparison.
Proprioception
- Move thumbs and big toes up or down while patient’s eyes are closed, asking for direction.
- Grasp digits from the sides and wiggle before moving to mask starting position.
Higher-Order Sensation
- Graphesthesia: Draw numbers, letters, or shapes on palm with blunt object and ask patient to identify.
- Stereognosis: Place common objects in the hand for the patient to identify by touch.
Double Simultaneous Stimulation
- Touch left, right, or both sides with light touch; patient identifies the side(s) touched.
- If unable to identify both simultaneously, suspect cortical sensory pathway involvement.
Balance (Romberg Test)
- Patient stands with feet together and arms extended; observe for balance with eyes closed.
- Apply gentle pushes to test postural stability.
Key Terms & Definitions
- Graphesthesia — Ability to identify symbols traced on the skin.
- Stereognosis — Ability to identify objects by touch alone.
- Proprioception — Sense of position and movement of body parts.
- Romberg Test — Assessment of balance with eyes closed and feet together.
- Double Simultaneous Stimulation — Technique to test perception of touch on both sides of the body at once.
Action Items / Next Steps
- Practice each sensory test on a partner.
- Review cutaneous nerve distributions for upper and lower limbs.
- Study the clinical implications of abnormal findings in each sensory modality.